part of part of develops from develops from foregut ruminant forestomach https://upload.wikimedia.org/wikipedia/commons/2/2b/Abomasum_(PSF).png forestomach Any of the first three stomachs of a ruminant, i.e., the rumen, reticulum, or omasum. UBERON:0007359 BTO:0000480 You will still see the statement in some texts that the parts of the forestomach are derived from the embryonic esophagus, and that's the reason why (like the esophagus) they're lined with stratified squamous epithelium. This is open to doubt. While there is no doubt that the rumen, reticulum, and omasum are all derived from the embryonic foregut, there is evidence to indicate that all three come from that an area of the foregut homologous to the part that develops into the single stomach of non-ruminants. If this is so, then the forestomach can be considered diverticula (or derivatives) of the stomach proper, not the esophagus, despite the nature of the lining -- http://www.vetmed.vt.edu/education/curriculum/vm8054/labs/lab21/Examples/exrumen.htm ruminant stomach stomach non-glandular region